There is nothing better than sweating out all that bad mojo at the gym, especially when you’ve got a bunch of haters pumping you up in your head (their negative comments are waaay better than a five-hour energy drink!). But what about on the days when you don’t feel like punching someone in the face, even though you know you should really go for that 500-calorie burn? Well, taking a class in High Intensity Interval Training (or HIIT) will cut out your work for you, because even if you’re not feeling the motivation, you’re going to feel the burn. HIIT combines strength and cardio training into short, intense ratios, designed for maximum fat burnage. While this workout is not relatively new, it is becoming increasingly popular at gyms and at home- so you can expect a gradual fading out of Zumba and Spinning this year. It may sound like just another bandwagon to hop on (or steer far away from, for the sake of your glutes and wallet), but HIIT has actual, crazy results. One disclaimer, though: you may gain a few new haters, but only because they’ll be jealous of your rockin’ bod. Sounds like a fair deal to me.